Uniform Circular Motion Rectangular viewpoint
x = r cos(q) = r cos(qo+wt)
y = r sin(q) = r sin(qo+wt)
Now we use: vx = dx/dt and vy = dy/dt:
vx = dx(t)/dt = dx(?)/dq * dq(t)/dt =
r (- sin(q) ) * w = -w r sin(qo+wt)
vy = dy(t)/dt = dy(?)/dq * dq(t)/dt =
r (+cos(q) ) * w = w r cos(qo+wt)